peache



No Model.) 3 Sheets-Sheet 1 J..O. PEAGHE. STEAM ENGINE.

No. 546,900. Patented Sept. 24, 1895.

wz 'z I J /aw 61m W l g V/ 14 7 Awa 3 Sheets-Sheet 2. J. O. PEAOHE.

STEAM ENGINE.

[No Model.)

Patented Sept. 24, 1895. r

ANDREW EGRANAM. PHUTU-LFTHO.WASHINGTDN DYC.

(No Model.) 3 Sheets-Sheet 3.

J. O. PEAGHE. STEAM ENGINE.

No. 546,900. Patented Sept. 24, 1895.

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ATENT JAMES COURTHOPE PEAOHE, OF LONDON, ENGLAND.

STEAM-ENGINE.

JL 'EOIFICATION forming part of Letters Patent No, 546,900, datedSeptember 24, 1895.

Application filed April 16, 1892. Serial NoAZQAOB, (No model.) Patentedin England August 2'7,1891,N0-l4,526.

To all whom, it ntay concern.-

Be it known that I, JAMES COURTHOPE PEACHE, associate member InstituteOivil Engineers, engineer, a subject of the Queen of Great Britain andIreland, residing at Park Cottage-,Thames Ditton,London,in the county ofSurrey, England, have invented Improvements in Compressed Air and SteamEngines, (for which I have received Letters Patent in Great Britain, No.14,526, dated August 27, 1891,) of Which the following is aspecification, which will enable others skilled in the art to which itappertains to make and use the same, reference being made to theaccompanying drawings.

My invention relates to improvements in engines driven by compressed airor steam; and its object is to ettect the absorption of the momentumwhich the reciprocating parts of the engine-viz., the pistons, valves,their rods and c0nnectionsacquire during their motion away from thecrank-shaft. As a consequence a balance of pressure is always maintainedin the direction of the said shaft and all knocking in the joints of thesaid parts as well as in their several junctions prevented.

In carrying my invention into efteotI make use of a piston and cylinderhereinafter referred to as the controlling-piston andcontrolling-cylinder. This combination is equally applicable to alltypes of engines irrespective of the relative positions of the cylinderand the crank-shaft.

The expression steam wherever hereinafter used is to be taken asincluding compressed air.

The controlling-piston is rigidly connected to the parts which it isintended to control and works with a reciprocating stroke in thecontrolling-cylinder. When it is at or near the beginning of its stroke,steam under pressure is admitted by suitable gear and cut off shortlyafter the piston has commenced its stroke. The steam then expands duringthe remainder of the stroke, and on the return stroke it is compressedabove the piston until at or near the end of the return strokecommunication is again opened to the steamsupply. It is the pressureabove the returning piston that is the operative agent of thisinvention, and provision for its adjustment to the requirements of thecase is made by varying either the area of the piston or the initialpressure of the steam or the capacity of the clearance-space in thecylinder at the top of the stroke or, within certain limits, by thepoint at which the steam is admitted to or cut off from the cylinder, orby a combination of two or more of the above methods.

To absorb the momentum of the main reciprocating parts on the returnstroke in a single-acting steam-engine the controlling apparatus orarrangement above described is used to assist the back'pressure andcompression obtained by the usual distribution of steam in the Workingcylinders of the engine on the return stroke of the pistons.

To'regulate the admission of steam at the commencement of the stroke inthe apparatus described above, I usually employ a pistonvalve connectedto the controlling-piston by a rod and working in a valve-cylinder thatopens directly into the controlling-cylinder. In a suitable position inthe side of the valvecylinder ports are formed,- having a connectionwith the steam-supply. At the commencement of the stroke of thecontrollingpiston these ports are uncovered by the piston-valve andsteam is admitted above the controlling-piston. As thecontrolling-piston commences its stroke it carries the pistonvalve withit, which latter covers the ports and thus cuts off the supply of steamto the controlling-cylinder. The steam expands in thecontrolling-cylinder during the remainder of the stroke of the pistonand is compressed on the return stroke of the controlling-piston untilthe piston-valve again uncovers the ports in the valve-cylinder, whenthe controlling-cylinder is again placed in communication with thesupply of steam. In asimplei. e., single-expansion single-actingengine Iuse the lower side of the controlling-piston as a working piston andplace the upper side of the piston valve in direct communication withthe steam-chest or source of steam-supply. In a tandem compoundt'. 6.,doubleexpansion siugle-actingengine I place the first expansion-cylinder immediately over the second expansion-cylinder withoutany diaphragm or cover between them and use the upper side of the secondexpansion-piston as a controlling-piston and the first expansionpistonas a piston-valve for regulating the admission of steam above the secondexpansion or controlling piston.

In an engine arranged in accordance with the preceding paragraph steamis admitted above the first expansion-piston by suitable valves andvalve-gear, and toward the lower end of its stroke the firstexpansion-piston uncovers a row of holes around the wall of the firstexpansion-cylinder. These holes communicate with the receiver and allowsome of the steam to escape from the first expansioncylinder into thereceiver, a further portion of the steam contained in the firstexpansioncylinder at the end of its stroke being exhausted into thereceiver on the return stroke of the first expansion-piston by valves inthe usual manner. The first expansion-piston is made of a depth somewhatless than the stroke of the engine, so that at the top of its stroke therow of holes referred to above is uncovered bythe lower edge of thefirst expansionpiston, and thus steam is allowed to pass from thereceiver into the space between the first expansion and second expansionpistons. On the next downstroke the first expansion-piston again coversthese holes, thus cutting off the supply of steam above the secondexpansion or controlling piston. Steam is admitted from the receiver tothe under side of the second expansion-piston and exhausted by means ofvalves in the usual manner.

In the accompanying drawings, which are to be taken as part of thisspecification and read therewith, Figure l is a sectional elevationillustrating my invention in its simplest form. Fig. 2 is a sectionalelevation of a single-expansion single-acting engine constructedaccording to my invention. Fig. 3 is a sectional elevation of adouble-expansion singleacting engine constructed according to myinvention. Fig. 4 is a sectional elevation of a modified form ofdouble-expansion singleaeting engine constructed according to myinvention.

In Figs. 1, 2, 3, and at the fiy-wheel, crankshaft, eccentric, andeccentric-rod or their equivalents, with their connections, are omitted,but may be of any suitable or well-known type.

Referring to Fi 1, a is the controlling-cylinder, and Z) thecontrolling-piston. c is part of the rod by which the controlling-pistonis rigidly connected to the working piston or other reciprocating partof the engine which it is intended to control. (1 is the steam-supply. cis the valve-cylinder. It is an axial extension of thecontrolling-cylinder a, with which it communicates. f is a piston-valveworking in the cylinder e. g is the rod by which the valve is connectedto the controlling-piston b. h h are steam-ports in the valve-cylinder."Z is a closed chamber constructed upon the annular cover a of thecontrolling-cylinder and standing over the valvecylinder. Thesteam-supply cl opens into it. The action of the controlling combinationabove described is as follows: The controlling-piston and its valve arerepresented as standing at the top of their stroke. Vhen the engine isstarted, steam fiows into the space above the piston 11 through ports 7L7L until the piston-valve f, as it travels downward, passes over theseports and cuts off the supply of steam. The steam inclosed above pistonZ) then expands in the controlling-cylinder during the remainder of thedownstroke and is compressed again on the return stroke until at or nearthe top of the stroke the piston-valvefagain uncovers the ports h h andagain places the upper side of piston bin communication with the sourceof stean1-supply. The momentum of the reciprocating parts to becontrolled is absorbed by the pressure of steam above the piston b onthe return stroke.

In a single-acting engine there should always be sufficient pressureagainst the bearings of the reciprocating parts on the upward stroke tokeep them always pressed in a downward direction, but not more pressurethan is sufficient for the purpose. The correct amount of pressure canbe provided for by properly proportioning the parts described.

The above remarks about singleacting engines are applicable to the otherforms of engines described in this specification.

In Fig. 2 is shown the application of my controlling apparatus to asingle-expansion single'acting engine. I) is the controlling-piston, anda is the controlling-cylinder. The under side of the piston 12 and thelower end of the cylinder at are used as the working piston and,cylinder, respectively. 0 is the ordinary piston-rod, through which thecontrolling and working piston is connected to the crank-shaft. g is anextension of the pistonrod, to which the piston-valve f is connected.This piston-valve works in a cylinder 0, that is placed axially over themain cylinder a. h h are ports in the side of cylinder 6 for admittingsteam above the controlling-piston. D is the main steam-supply, and dthe branch supply to the closed chamber 2'. m is the slide-valve, (shownas of the piston-valve type,) and k is the valve-rod. m is thevalvecylinder, 0 the steam-port to the cylinder a, and o the mainexhaust. The action of the steam above the controlling-piston b is thesame as that described in connection with Fig. 1, and for that reasonthe same reference-letters are used. Steam is admitted to the under orworking side of piston Z) by valve m" and port 0 during the upstroke andexhausted on the downstroke in the usual manner.

Referring to Fig. 3, p is the first expansionpiston working in cylinder1). 'r is the second expansion-piston working in cylinder 1"". These twopistons are connected together by the trunk 19 c is the usualpiston-rod. p is the steam-port to the first expansion-cylinder, and ris the steam-port to the second expansion-cylinder. D is the mainsteam-supply, and o the main exhaust. The slide-Valve (1' works inacylinder or steam-chest g. It is shown as of the hollowtreble-piston-valve type. (1 q are valverings. g is the valverod. g gand g g are holes for the passage of steam. The upper side 0" of thelow-pressure piston 0" acts as the controlling-piston and the upper partof the cylinder r as the controlling-cylinder. The firstexpansion-piston 1) acts as a piston-valve for regulating the admissionof steam to the upper or controlling side of the piston r. r is a portformed in the side of the cylinder 19.

The action of the engine and controlling combination is as follows: Inthe position shown steam is being admitted by valve g and port 29 to theupper side of the first expansion-piston p, and steam at the fullpressure of that above this piston passes by port 1' to the annularspace r and upper side of piston r. Shortly after the commencement ofthe downstroke the pistonp passes over the end of port r thus cuttingoff the supply of steam above the piston 0. Steam expands above thispiston for the remainder of the stroke and is compressed again on thereturn stroke in the manner already described in connection with otherapplications of my controlling apparatus. On the return or up stroke ofthe piston 19 steam exhausts through port 13 and holes g g into theinterior of the hollow piston-valve q, and thence by holes g g and port0* into the second expansion or low-pressure cylinder 7- The exhaustfrom this cylinder on the downstroke is by port 7"", past the end of thevalve g to the main exhaust 0 To facilitate the starting of an enginesuch as shown in Fig. 3 I place a valve 0, as shown, near the top of thelow-pressure cylinder 1 but sufficiently low down, so that the firstexpansion-piston 19 shall cover the port r before the low-pressurepiston r uncovers the aperture r leadingto the valve 1. This is toprovide that there shall not be a blow through of steam from the firstexpansion-cyh inder on opening the valve 1. I also place a valve 1"between the main steam-supply D and the lower or intermediate receiverpart of valve-cylinder g. In the position shown the two valves areclosed, and the engine then works as a single-acting engine, as alreadydescribed. If, however, the valve 0" is turned so as to open acommunication between the main steam-supply D and the intermediatereceiver, the engine will Work as a double-acting engine, for there willbe no pressure in the space r between the first and secondexpansion-pistons except just at the top of their stroke. The pressurein the high-pressure steam-chest and in the intermediate receiver is thesame, because the Valve r formsa free communication between them. On thedownstroke the steam-pressure acts on the upper side of the firstexpansion-piston p, forcing it down, (the under side of the low-pressurepiston being then in communication with the exhaust 0 and on theupstroke the pressures per square inch on the under side r of thelowpressure piston and on the upper side of the high-pressure pistonpbeing the same, (for both are then in communication with the receiverand steam-supply D,) the total pressure on the under side of thelow-pressure piston, owing to its greater area, exceeds that on theupper side of the first expansion-piston and forces the pistons up. Theengine thus works as a double-acting engine until the valve 1" isclosed.

r is a steam-jacket provided for preventing condensation of steam in thefirst expansion and controlling cylinders.

Referring to Fig. 4, this engine is similar to that shown in Fig. 3, butdiffers from it in that steam for the controllingcylinder is taken fromthe intermediate receiver instead of from the steamsupply. The port istherefore dispensed With, because it becomes unnecessary. sis theintermediate receiver. 8' s are the ports through which it communicateswith the controlling-cylinder and the Valve-chest, respectively. Thefirst expansion-piston p is made rather shorter than the stroke of theengine. It is attached to the low-pressure piston by an extension 9 ofthe main piston-rod. At the lower end of the stroke the firstexpansion-piston uncovers the port 5 and allows a portion of the steamcontained in the high-pressure cylinder to escape into the intermediatereceiver. At the top of the stroke the lower edge of the piston 19uncovers the ports 3' s and steam flows from the receiverinto the spaceabove the controling-piston r.

The other parts of Fig. 4 and their working are identical with thecorresponding parts of Fig. 3and are marked with the samereference-letters, respectively.

I wish to call attention to the fact that in the double-expansionengines illustrated in Figs. 4 and 5 the construction and arrangement ofthe slide-valve q provides for steam only at the pressure in theintermediate receiver being behind the valve-rings g g and g and thatthis, while sufficient to press them out and keep them steam-tight, doesnot subject them to so much wear as would steam at the full pressure.

I claim 1. The combination of controlling cylinder closed throughout itssides and one of its ends with the exception of a communication throughthe latter to the valve cylinder; valve cylinder of smaller sectionalarea than the controlling cylinder, aligned therewith and joined to thesaid closed end thereof; controlling piston rigidly held to thereciprocating member of the engine to be controlled and adapted to moveto and fro in the controlling cylinder; valve rigidly held to thecontrolling piston at a distance from it not less than the length of thestroke of the latter and adapted to move to and fro in the valvecylinder aforesaid; and a port or ports in the said valve cylinder whichcommunicate with the supply and are adapted in respect of their positionin the said valve cylinder to be opened by the valve only at thecommencement of the working stroke and at the end of the return stroke.

2. The combination of controlling cylinder closed throughout its sidesand one of its ends with the exception of a communication through thelatter to the valve cylinder; valve cylinder of smaller sectional areathan the controlling cylinder, aligned therewith and joined to the saidclosed end thereof; piston adapted to move to and fro in the firstmentioned cylinder; port and valve adapted to regulate the supply to andexhaust from the working face of the said piston; a valve rigidly heldto the said piston at a distance from it not less than the length of thestroke of the latter and adapted to move to and fro in the valvecylinder above mentioned, and a port or ports in the said valve cylinderwhich communicate with the supply and are adapted in respect of theirposition in the said valve cyl-' inder to be opened by the valve only atthe commencement of the working stroke and at the end of the returnstroke.

3. The combination of high and low pressure pistons on the same pistonrod and adapted to work within the high and low pressure cylindersrespectively; high and low pressure cylinders aligned and communicatingwith each other; a port establishing a communication between the supplyand the space between the two pistons aforesaid until it is closed bythe outstroke 0f the high pressure piston; ports from the valve cylinderor steam chest to the outer ends of the high and low pressure cylinders,respectively, and a reciprocating valve working in the said valvecylinder or steam chest to distribute the steam to the said high and lowpressure cylinders successivelyand to control the exhausts therefrom.

4. The combination of high and low pressure pistons on the same pistonrod, and adapted to work within the high and low pressure cylindersrespectively; high and low pressure cylinders aligned and communicatingwith each other; a port establishing a communication between the supplyand the space between the two pistons aforesaid until it is closed bythe out-stroke of the high pressure piston; a controllable branch supplyfrom the main supply to the intermediate receiver; ports from the valvecylinder or steam chest to the outer ends of the high and low pressurecylinders, respectively, and a reciprocating valve working in the saidvalve cylinder or steam chest to distribute the steam to the said highand low pressure cylinders successively and to control the exhausttherefrom.

In testimony whereof I have hereunto atfixed my signature, in presenceof two witnesses, this 16th day of March, 1892.

J. COUR'll-IOPE PEACIIE.

Vitnesses:

HENRY H. LEIGH, T. F. BARNES.

